1. Waverider Configurations
2. location below the body i s accurate. It is probable that there w i l l be a shock-boundary layer interaction i n the tip region which can cause separation. Que to i t s limitations, the full potential method cannot predict separation or its effects. No details concerning the viscous nature of the flow were reported i n reference 8, therefore, it is difficult to estimate if boundary layer separation did or did not occur i n the tip region. For the Mach 4 elliptic cone waverider the bow shock was for the m s t part located Outside the tip region or was just intersecting the tip. Reference 12 discusses both waverider configurations with respect to fully-optimized waveriders and concludes that the Mach 6 waverider's performance (L/D) is less than that expected for an timized waverider with the same volume ratio (v2B/s) and slenderness ratio (Ab/S) where V i s the volume, Ab, the base area, and S, the projected planform area. The elliptic cone waverider, on the other hand, agrees well or is only slightly below the values predicted for a fullyoptimized waverider. Therefore, fran a design standpoint it i s desirable to avoid shock interactions inside the l i p region which w i l l prevent the attainment of the best lift-to-drag ratio. A comparison between theoretical and experimental surface pressures along the lower surface for an angle-of-attack range is shown i n figure 18. Again, there i s good agreement with data up to a point i n the tip region for Mach number angle-ofattack combinations where 145 is not much greater than one (e.g., for M=6, a=4, M6 is approximately 1.8). Nonconical Waverider - Confined Flow Field Model
3. Validation of the full potential code as an analysis tool has to this point centered on i t s use with conical geometries, in this case waverider configurations. An experimental investigation has been initiated at NASA-Langley which w i l l provide experimental data on a nonconical waverider concept called the Confined Flow Field (CFF) model. A sketch of this configuration is shown in figure 19. As shown i n the side view, the curved upper surface does not l i e along rays emnating from the nose, therefore the geometry is not conical. Nonconical geometries either analytically defined or fit analytically have been previously studied? s4 An option i s now available which allows analysis of nonconical geometries via the input of discrete numerical points. In general, obtaining an analytical fit for a configuration w i l l be difficult and time consuming, therefore, this option should prove extremely useful for analyzing complex configurations. This latter option has proved extremly useful when analyzing complex configurations. Reference